Limestone karsts across southern China to south-eastern Asia support high levels of species diversity and endemism. Tao et al. studied the molecular evolution of the Ca2+-permeable channel TPC1 in the genus Primulina, a group of plants that have adapted to calcium-rich soils.
Molecular evolution analyses of Primulina TPC1 identified several sites under positive selection, which suggests that TPC1 may participate in local adaptation of Primulina to karst environments: this episodic diversifying selection may play a major role in TPC1 molecular evolution.
Tao, J., Feng, C., Ai, B., & Kang, M. (2016). Adaptive molecular evolution of the two-pore channel 1 gene TPC1 in the karst-adapted genus Primulina (Gesneriaceae). Annals of Botany, 118(7), 1257–1268. https://doi.org/10.1093/aob/mcw168